The overall objective of the research proposed in this application is to determine the integral membrane components involved in the transmembrane control of cell substratum adhesion. Preliminary work in this laboratory has shown that control baby hamster kidney (BHK21/C13) fibroblasts will round up and detach from the substrate when treated with a broad spectrum antiserum to purified BHK surface membranes. Extensive alterations in surface morphology and cytoskeletal organization result from this treatment. Protocols for purification of molecules involved in these antiserum induced responses have resulted in the isolation of a highly restricted population of integral membrane glycoproteins of 120-140 Kd Mr which can block the effect of the antibody. Experiments with murine mammary epithelial cells result in the isolation of a similar class of adhesion-related glycoproteins. Thus this class of glycoproteins may be relatively conserved. The experiments proposed in this application are designed to (1) make both monospecific polyclonal antibodies in goats and monoclonal antibodies in mice to components in this glycoprotein fraction from fibroblasts, (2) determine the effect of these antibodies on the behavior of living cells, (3) localize the antigens on the surface of adherent and suspension cells in culture and in vivo, and (4) determine the behavior of these surface antigens with respect to fibronectin and cytoskeletal components following experimental manipulation of the substrate, cell surface of cytoskeleton. Once specific antibodies for integral membrane components have been obtained, it will be possible to use these probes to purify large quantities of their respective antigens for structural and functional studies and in the future to begin to investigate the control of expression of these antigens in normal cells and in cells whose adhesive properties have been altered by mutation or by malignant transformation. This body of experiments should increase our understanding of the transmembrane signaling mechanisms which determine the social behavior and adhesiveness of both normal and transformed cells.